Thermostatically controlled valve especially for engines of motor vehicles

ABSTRACT

A thermostatically controlled valve with a valve main closure disc and a valve short-circuit closure disc, especially for the cooling water overflow line from the engine to the radiator of a motor vehicle which is characterized by the combination of an anticipatory control and of a knife edge seat of the valve ring with a sharp edge, in which the edge and/or the abutment surface for the edge consist of highly resistant, non-oxidizing material.

Mischke THERMOSTATICALLY CONTROLLED VALVE ESPECIALLY FOR ENGINES OF MOTOR VEHICLES v [75] Inventor: Arthur Mischke, Ruit Esslingen,

Germany v [73] Assignee: Daimler-Benz Aktiengesellschaft,

Stuttgart-Untertuerkheim, Germany [22] Filed: Apr. 13, 1971 [21]. Appl. No.: 133,567

[30] Foreign Application Priority Data Apr. 14, 1970 Germany 2017759 [52] US. Cl. 236/34.5, 251/333 [51] Int. Cl. F0lp 7/16 [58] Field of Search 236/34, 34.5, 100; 251/333 [56] References Cited UNITED STATES PATENTS 489,324 l/l893 Patterson 251/333 x 925,729 6/1909 Speer 25l/33 3 2,829,835 4/1958 Branson 236/34.5

[ June 18, 1974 3,172,602 3/1965 Drapeau 236/34.5

3,207,437 9/1965 Bailey 236/34 3,365,130 1/1968 Kamin et a1. 236/34.5 FOREIGN PATENTS OR APPLICATIONS 1,035,408 7/1958 Germany 236/34.5

546,502 9/1957 Canada 251 /333 OTHER PUBLICATIONS Material Selector, Materials Engineering Nov. 1970 pp. 71 & 72, A Reinhold Publication Primary ExaminerWi1liam E. Wayner Attorney, Agent, or Firm-Craig and Antonelli [5 7] ABSTRACT A thermostatically controlled valve with a valve main closure disc and a valve short-circuit closure disc, especially for the cooling water overflow line from the engine to the radiator of a motor vehicle which is characterized by the combination of an anticipatory control and of a knife edge seat of the valve ring with a sharp edge,v in which the edge and/or the abutment surface for the edge consist of highly resistant, nonoxidizing material.

17 Claims, 2 Drawing Figures PATENTEDJumnu v 3.817...d50

22 v INVENTOR ARTHUR MISCHKE ATTORNEYS 1 v THERMOSTATICALLY CONTROLLED VALVE ESPECIALLY FOR ENGINES OF MOTOR VEHICLES The present invention relates to a thermostatically controlled valve with a valve inain closure disc and a valve short-circuiting or by-pass disc, especially in the cooling water overflow line from engine to radiator of a motor vehicle.

A thermostatically controlled valve of the aforementioned type is known in the prior art in which the main closure disc abuts against a knife-edge-like ring of the valve housing and thereby closes the water line to the radiator with a cold engine. The knife-edge of the ring is seated on the flat bottom side of the cylindrically constructed valve main closure disc. The valve by-pass closure disc of this prior art valve is connected with the valve main closure disc by way of spacer pins and interconnected springs and is guided by these pins. With the known, thermostatically controlled valve, the soiling danger and therewith a nonpermissively high leakage water quantity'could be avoided far-reachingly due to 'the knife edge seat construction. However, investiga tions have established the fact that during the beginning of the opening of the valve main closure disc of the thermostat, vibrations occurred which continued as pressure vibrations in the cooling-water and become effective in a disadvantageous manner onthe durability of the heat-exchangers installed in the vehicle.

It has also become known in connection with thermostatically controlled valves to utilize a so-called precontrol or anticipatory control for the prevention of the fluttering of the valve main closure disc during the opening operation, by which harmful pressure vibrations are produced. With this pre-control or anticipatory control, either the valve seat ring or the valve main closure disc is constructed at its rim as knife edge and is seated in the closed condition against the outer surface inclined to the valve axis of the counter-piece whereby the counter-piece is constituted either by the valve main closure disc or by the valve seat ring. However, it has proved particularly disadvantageous with this type of construction of the thermostatically controlled valve that dirt particles may become jammed or wedged between the seating surfaces of the valve seat and valve disc whereby larger leakage water quantities may occur. As has been demonstrated in operation of this valve, also in particular sharpened knife edges at the valve seat ring or at the valve main closure disc cannot prevent completely the wedging-in of dirt particles whereby the dirt particles are even pressed in part into the knife-edge by reason of the high closure pressure and the valve therefore does not properly close any longer.

The present invention is concerned with the task to avoid the disadvantages of the known valves and to provide a thermostatically controlled, safely closing valve, in which the flow conditions are improved by a suitable arrangement and construction of the valve discs and of the valve closure parts, and in whichno critical vibrations occur during the opening and closing of the. valve main closure disc and of the valve shortcircuit closure disc.

The underlying problems are solved by the thermostatically controlled valve in accordance with the present invention which is characterized by the combination of an anticipatory control or pre-control and of a knife edge seat of the valve seat ring with a sharp knife edge, in which the edge and/or abutment surface consist of highly resistant non-oxidizing material. In a particular construction of the present invention, the precontrol may consist of the valve main closure disc which is constructed as pot with walls inclined to the valve axis, and of the sharp highly resistant knife edge of the valve seat ring which in the closed condition rests on the outer wall of the valve main closure disc. Advantageously, the knife edge and the seat thereof on the outer wall of the funnel may consist preferably of V2A- steel and may be finely machined and possibly be hardened. Since the machining and manufacture of the valve main closure disc from VZA-steel is connected with high costs, it is also possible within the scope of the present invention to make the valve main closure disc of another material and to construct only the seating surface from a separately manufactured ring consisting of highly resistant, non-oxidizing material.

It is prevented by this construction of the closure parts of the thermbstat that dirt deposits collect at the knife edge seat. A completely satisfactory closing of the valve main closure disc would be prevented by dirt deposits, for example, of moldsand left behind in the head of cast cylinder heads, between the sealing surface of valve seat ring and valve disc, which would have, as a consequence, larger leakage water quantities. The flow conditions in the thermostatically controlled valve are decisively improved by the funnelshaped construction of the valve main closure disc. During the opening operation, the cooling water can flow unimpairedly along the funnel-shaped walls of the valve main closure disc so that the spring-loaded main valve closure disc does no longer have any tendency to vibrations or fluttering. The pressure vibrations dangerous for the heat-exchanger are thereby avoided completely.

Accordingly, it is an object of the present invention to provide a thermostatically controlled valve, especially for engines of motor vehicles which avoids by simple means the aforementioned shortcomings and drawbacks encountered in, the prior art. I

Another object of the present invention resides in a thermostatically controlled valve which eliminates the danger of fluttering or pressure vibrations during opening thereof.

A further object of the present invention resides in a thermostatically controlled valve, especially for the engines of motor vehicles, which avoids the deposit of dirt at the seating surfaces of valve seat and valve disc and therewith the danger of undesirable water leakages.

Still another object of the present invention resides in a thermostatically controlled valve which is simple in construction yet is reliable in operation as regards its completely satisfactory closing.

These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, two embodiments in accordance with the present invention, and wherein:

FIG. 1 is a schematic cross-sectional view of an installed thermostatically controlled valve in the cooling water overflow line with a knife edge seat construction in accordance with the present invention; and

FIG. 2 is a partial cross-sectional view, on an enlarged scale, of a modified construction of the knife edge seat.

Referring now to the drawing wherein like reference numerals are used through the two views to designate like parts, and more particularly to FIG. 1, this figure illustrates a schematic view of the installed thermostatically controlled valve in the cooling water overflow line. The line 1 leads to the vehicle radiator 30, the line 2 to the cooling water pump 31, and the line 3 comes from the engine 32. In the illustrated position, the thermostatically controlled valve is closed in the direction toward the radiator 30. Consequently, the cooling water pump 31 pumps the cooling water only through the engine 32.

The thermostatically controlled valve essentially consists of a frame body generally designated by reference numeral 4 with an upper bracket 5 and a lower bracket 6. The valve seat ring 7 is clamped fast between the two brackets 5 and 6. A wax cartridge generally designated by reference numeral 8 is secured at the upper bracket 5 by means of a threaded connection 9. The wax cartridge 8 is provided at its upper end with a collar 10 against which is pressed the valve main closure disc 11 by means of a compression spring 12 which is supported at the lower bracket 6 of the frame body 4. At its lower end, the wax cartridge 8 includes a coneshaped ofiset l3 and is extended by a cylindrical portion 14 with a terminal collar 15. The valve shortcircuit or by-pass closure disc 16 is guided on the cylindrical portion 14 and is pressed against the collar by means of a compression spring 17. Whereas the compression spring 12 is supported against the lower bracket 6, the compression spring 7 is supported against the cone-shaped offset 13 of the wax cartridge 8.

In the closed condition of the thermostatically controlled valve, in which the cooling water is circulated only through the engine by means of the cooling water pump (corresponding to the full line arrows in the figure), the knife edge 18 of the valve seat ring 7 rests against the outer wall 19 of the funnel-shaped valve main closure disc 11. The knife edge seating surfaces of the funnel and of the knife edge 18 of the valve seat ring 7 are made from highly resistant non-oxidizing material, preferably V2A-steel.

Another knife-edge seat construction is illustrated in FIG. 2 on a larger scale. it differs from the knife edge seating construction according to FIG. 1 in that the knife edge made from VZA-steel is provided at the valve seat ring 7 and is seated in the closed condition of the valve on an abutment ring 22 on the outer surface of the valve main closure disc. Expensive material can be economized by this measure.

lf now the cooling-water with increased operating temperature of the engine warms up, then the wax cartridge 8 expands so that the valve main closure disc 11 is pressed downwardly opposite the spring force of the spring 12 and simultaneously the valve by-pass closure disc 16 rests against the seating surface 20. As a result thereof, the cooling line 3 coming from the engine is connected directly with the cooling line 1 leading to the heat-exchanger and the cooling line 2 leading directly to the cooling water pump is closed. During the opening operation, as a result of the favorable construction of the valve main closure disc as regards stream-lining, no vibrations and no fluttering can occur any longer.

The guidance of the valve main closure disc 11 is independent of the guidance of the valve by-pass closure disc 16 and also the function of the compression springs 12 and 17 is independent of one another so that also for that reason pressure vibrations are prevented.

While I have shown and described only two embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. A thermostatically controlled valve arrangement comprising:

first line means for supplying a fluid medium,

second line means for conducting said fluid medium away from said first line means,

third line means for conducting said fluid medium away from said first line means, said second and third line means being separate from one another,

first valve means for selectively blocking said second line means with respect to said first line means,

second valve means for selectively blocking said third line means with respect to said first line means,

and temperature responsive means for controlling said first and second valve means in response to the temperature of the fluid medium in said first line means,

said first valve means including a first valve seat and a first valve disc, said first valve disc having a first valve axis extending through a central portion thereof, said first valve seat and first valve disc being movable with respect to one another in the direction of said first valve axis from a position' blocking said second line means with respect to said first line means with said first valve seat sealingly engaging a peripheral edge portion of said first valve disc to an open position .with said first valve seat spaced from said first valve disc to permit fluid flow from said first line means to said second line means,

wherein said first valve seat is formed with a sharp edge tapering conically inwardly toward said first valve axis in the direction facing the flow from said first line means, and wherein said peripheral edge portion on said first valve disc tapers conically inwardly toward said first valve axis in the direction of the flow from said first line means such that said first valve seat and first valve disc form an annular funnel shaped opening diverging in the direction of fluid flow when said first valve seat is moved away from said first valve disc,

characterized by separate spring means urging the first valve disc and a second valve disc of the second valve means into their respective position independently of one another.

2. A thermostatically controlled valve arrangement comprising: 1

first line means for supplying a fluid medium,

second line means for conducting said fluid medium away from said first line means,

first valve means for selectively blocking said second line means with respect to. said first line means,

second valve means for selectively blocking said third line means with respect to said first line means,

and temperature responsive means for controlling said first and second valve means in response to the temperature of the fluid medium in said first line means,

said first valve means including a first valve seat and a first valve disc, said first valve disc having a first valve axis extending through a central portion thereof, said first valve seat and first valve disc being movable with respect to one another in the direction of said first valve axis from a position blocking said second line means with respect to said first line means with said first valve seat sealingly engaging a peripheral edge portion of said first valve disc to an open position with said first valve seat spaced from said first valve disc to permit fluid flow from said first line means to said second line means,

wherein said first valve seat is formed with a sharp edge tapering conically inwardly toward said first valve axis in the direction facing the flow from said first line means, and wherein said peripheral edge portion on said first valve disc tapers conically inwardly toward said first valve axis in the direction of the flow from said first line means such that said first valve seat and first valve disc form an annular funnel shaped opening diverging in the direction of fluid flow'when said first valve seat is moved awa from said first valve disc,

wherein said first valve seat and first "valve disc are configured such that said funnel shaped opening extends without reduction in size over the entire length of said first valve seat and first valve disc in the direction of flow from the position where said first valve seat and first valve disc abuttingly engage when in said position blocking said second line means with respect to said first line means.

3. Anarrangement according to claim 2, wherein said conically tapered peripheral edge portion extends in the flow direction beyond the place of engagement with said first valve seat.

4. An arrangement according to claim 2, further comprising an internal combustion engine, a vehicle radiator, and a cooling water pump for pumping cooling water to said engine, wherein said first line means is a cooling water outlet line leading from said internal combustion engine, wherein said second line means leads to said vehicle radiator, and wherein said third line means leads to said cooling water pump.

5. An arrangement according to claim 2, wherein said first valve seat and first valve disc are constructed, at least in the abuttingly engageable areas, of a highstrength, non-oxidizing steel alloy.

6. An arrangement according to claim 5, characterized in that said steel alloy is a VZA-steel.

7. An arrangement according to claim 6, characterized in that said steel alloy is hardened.

' 8. An arrangement according to claim 5, characterized in that said first valve seat is formed by walls of a housing for said first disc.

9. An arrangement according to claim 8, characterized in that said steel alloy is a VZA-steel.

10. An arrangement according to claimS, characterized in that said first valve seat is formed by an abut- 5 ment ring on outer walls of a housing for said first disk.

11. An arrangement according to claim 10, characterized in that said steelalloy is a V2A-steel.

12. An arrangement according to claim 2, characterdisk consist of highly resistant, non-oxidizing material.

13. A thermostatically controlled valve arrangement comprising:

first line means for supplying a fluid medium,

second line means for conducting said fluid medium away from said first line means,

third line means for conducting said fluid medium away from said first line means, said second and third line means being separate from one another,

first valve means for selectively blocking said second line means with respect to said first line means,

second valve means for selectively blocking said third line means with respect to said first line means,

temperature responsive means for controlling said first and second valve means in response to the temperature of the fluid medium in said first line means,

said first valve means including a first valve seat and a first valve disc, said first valve disc having a first valve axis extending through a central portion thereof, said first valve seat and vfirst valve disc being movable with respect to one another in the direction of said first valve axis from a position blockingsaid second line means with respect to said first line means with said first valve seat sealingly engaging a peripheral edge portion of said first valve disc to an open position with said first valve seat spaced from said first valve disc to per mit fluid flow from said first line means to said second line means,

and a frame body with first and second bracket means, wherein said temperature responsive means is a wax cartridge secured to one of said bracket means, said cartridge being provided witha first collar against which the first valve disc is urged by a spring force, said cartridge including a conical ofi'set as well as an extension provided at its free end with a second collar, said second valve means including a second valve disc which is urged against said second collar by a further spring force independent of said first-mentioned spring force,

wherein said first valve seat is formed with a sharp edge tapering conically inwardly toward said first valve axis in the direction facing the flow from said first line means, and wherein said peripheral edge portion on said first valve disc tapers conically inwardly toward said first valve axis in the direction of the flow from said first line means such that said first valve seat and first valve disc form an annular funnel shaped opening diverging in the direction of fluid flow when said first valve seat is moved away from said first valve disc.

14. An arrangement according to claim 13, characterized by a first spring resting with one end against the first valve disk and at the other against the other bracket means and a second spring resting with one end against said second valve disk and with the other end against said conical offset.

15. An arrangement according to claim 14, further comprising a frame body with first and second bracket means, wherein said temperature responsive means is a wax cartridge secured to one of said bracket means, said cartridge being provided with a first collar against which the first valve disc is urged by a spring force, said cartridge including a conical offset as well as an extension provided at its free end with a second collar, said second valve means including a second valve disc which is urged against said second collar by a further spring force independent of said first-mentioned spring force.

16. A thermostatically controlled valve arrangement comprising:

first line means for supplying a fluid medium,

second line means for conducting said fluid medium away from said first line means,

third line means for conducting said fluid medium away from said first line means, said second and third line means being separate from one another,

first valve means for selectively blocking said second line means with respect to said first line means,

second valve means for selectively blocking said third line means with respect to said first line means,

and temperature responsive means for controlling said first and second valve means in response to the temperature of the fluid medium in said first line means,

direction of said first valve axis from a position blocking said second line means with respect to said first line means with said first valve seat sealingly engaging a peripheral edge portion of said first valve disc to an open position with said first valve seat spaced from said first valve disc to permit fluid flow from said first line means to said second line means,

wherein said first valve seat is formed with a sharp edge tapering conically inwardly toward said first valve axis in the direction facing the flow from said first line means, and wherein said peripheral edge portion on said first valve disc tapers conically inwardly toward said first valve axis in the direction of the flow from said first line means such that said first valve seat and first valve disc form an annular funnel shaped opening diverging in the direction of fluid flow when said first valve seat is moved away from said first valve disc,

wherein said first valve seat and first valve disc are configured such that said funnel shaped opening diverges continuously along the entire length of said valve seat and first valve disc in the direction of said first valve axis from the position where said first valve seat and first valve disc abuttingly engage when in said position blocking said second line means with respect to said first line means.

17. An arrangement according to claim 16, further comprising an internal combustion engine, a vehicle radiator, and a cooling water pump for pumping coolsaid first valve means including a first valve seat and a first valve disc, said first valve disc having a first valve axis extending through a central portion thereof, said first valve seat and first valve disc being movable with respect to one another in the ing water to said engine, wherein said first line means is a cooling water outlet line leading from said internal combustion engine, wherein said second line means leads to said vehicle radiator, and wherein said third line means leads to said cooling water pump. 

1. A thermostatically controlled valve arrangement comprising: first line means for supplying a fluid medium, second line means for conducting said fluid medium away from said first line means, third line means for conducting said fluid medium away from said first line means, said second and third line means being separate from one another, first valve means for selectively blocking said second line means with respect to said first line means, second valve means for selectively blocking said third line means with respect to said first line means, and temperature responsive means for controlling said first and second valve means in response to the temperature of the fluid medium in said first line means, said first valve means including a first valve seat and a first valve disc, said first valve disc having a first valve axis extending through a central portion thereof, said first valve seat and first valve disc being movable with respect to one another in the direction of said first valve axis from a position blocking said second line means with respect to said first line means with said first valve seat sealingly engaging a peripheral edge portion of said first valve disc to an open position with said first valve seat spaced from said first valve disc to permit fluid flow from said first line means to said second line means, wherein said first valve seat is formed with a sharp edge tapering conically inwardly toward said first valve axis in the direction facing the flow from said first line means, and wherein said peripheral edge portion on said first valve disc tapers conically inwardly toward said first valve axis in the direction of the flow from said first line means such that said first valve seat and first valve disc form an annular funnel shaped opening diverging in the direction of fluid flow when said first valve seat is moved away from said first valve disc, characterized by separate spring means urging the first valve disc and a second valve disc of the second valve means into their respective position independently of one another.
 2. A thermostatically controlled valve arrangement comprising: first line means for supplying a fluid medium, second line means for conducting said fluid medium away from said first line means, third line means for conducting said fluid medium away from said first line means, said second and third line means being separate from one another, first valve means for selectively blocking said second line means with respect to said first line means, second valve means for selectively blocking said third line means with respect to said first line means, and temperature responsive means for controlling said first and second valve means in response to the temperature of the fluid medium in said first line means, said first valve means including a first valve seat and a first valve disc, said first valve disc having a first valve axis extending through a central portion thereof, said first valve seat and first valve disc being movable with respect to one another in the direction of said first valve axis from a position blocking said second line means with respect to said first line means with said first valve seat sealingly engaging a peripheral edge portion of said first valve disc to an open position with said first valve seat spaced from said first valve disc to permit fluid flow from said first line means to said second line means, wherein said first valve seat is formed with a sharp edge tapering conically inwardly toward said first valve axis in the direction facing the flow from said first line means, and wherein said peripheral edge portion on said first valve disc tapers conically inwardly toward said first valve axis in the direction of the flow from said first line mEans such that said first valve seat and first valve disc form an annular funnel shaped opening diverging in the direction of fluid flow when said first valve seat is moved away from said first valve disc, wherein said first valve seat and first valve disc are configured such that said funnel shaped opening extends without reduction in size over the entire length of said first valve seat and first valve disc in the direction of flow from the position where said first valve seat and first valve disc abuttingly engage when in said position blocking said second line means with respect to said first line means.
 3. An arrangement according to claim 2, wherein said conically tapered peripheral edge portion extends in the flow direction beyond the place of engagement with said first valve seat.
 4. An arrangement according to claim 2, further comprising an internal combustion engine, a vehicle radiator, and a cooling water pump for pumping cooling water to said engine, wherein said first line means is a cooling water outlet line leading from said internal combustion engine, wherein said second line means leads to said vehicle radiator, and wherein said third line means leads to said cooling water pump.
 5. An arrangement according to claim 2, wherein said first valve seat and first valve disc are constructed, at least in the abuttingly engageable areas, of a high-strength, non-oxidizing steel alloy.
 6. An arrangement according to claim 5, characterized in that said steel alloy is a V2A-steel.
 7. An arrangement according to claim 6, characterized in that said steel alloy is hardened.
 8. An arrangement according to claim 5, characterized in that said first valve seat is formed by walls of a housing for said first disc.
 9. An arrangement according to claim 8, characterized in that said steel alloy is a V2A-steel.
 10. An arrangement according to claim 5, characterized in that said first valve seat is formed by an abutment ring on outer walls of a housing for said first disk.
 11. An arrangement according to claim 10, characterized in that said steel alloy is a V2A-steel.
 12. An arrangement according to claim 2, characterized in that both of said first valve seat and first valve disk consist of highly resistant, non-oxidizing material.
 13. A thermostatically controlled valve arrangement comprising: first line means for supplying a fluid medium, second line means for conducting said fluid medium away from said first line means, third line means for conducting said fluid medium away from said first line means, said second and third line means being separate from one another, first valve means for selectively blocking said second line means with respect to said first line means, second valve means for selectively blocking said third line means with respect to said first line means, temperature responsive means for controlling said first and second valve means in response to the temperature of the fluid medium in said first line means, said first valve means including a first valve seat and a first valve disc, said first valve disc having a first valve axis extending through a central portion thereof, said first valve seat and first valve disc being movable with respect to one another in the direction of said first valve axis from a position blocking said second line means with respect to said first line means with said first valve seat sealingly engaging a peripheral edge portion of said first valve disc to an open position with said first valve seat spaced from said first valve disc to permit fluid flow from said first line means to said second line means, and a frame body with first and second bracket means, wherein said temperature responsive means is a wax cartridge secured to one of said bracket means, said cartridge being provided with a first collar against which the first valve disc is urged by a spring force, said cartridge including a conical offset as well as an extension provided at iTs free end with a second collar, said second valve means including a second valve disc which is urged against said second collar by a further spring force independent of said first-mentioned spring force, wherein said first valve seat is formed with a sharp edge tapering conically inwardly toward said first valve axis in the direction facing the flow from said first line means, and wherein said peripheral edge portion on said first valve disc tapers conically inwardly toward said first valve axis in the direction of the flow from said first line means such that said first valve seat and first valve disc form an annular funnel shaped opening diverging in the direction of fluid flow when said first valve seat is moved away from said first valve disc.
 14. An arrangement according to claim 13, characterized by a first spring resting with one end against the first valve disk and at the other against the other bracket means and a second spring resting with one end against said second valve disk and with the other end against said conical offset.
 15. An arrangement according to claim 14, further comprising a frame body with first and second bracket means, wherein said temperature responsive means is a wax cartridge secured to one of said bracket means, said cartridge being provided with a first collar against which the first valve disc is urged by a spring force, said cartridge including a conical offset as well as an extension provided at its free end with a second collar, said second valve means including a second valve disc which is urged against said second collar by a further spring force independent of said first-mentioned spring force.
 16. A thermostatically controlled valve arrangement comprising: first line means for supplying a fluid medium, second line means for conducting said fluid medium away from said first line means, third line means for conducting said fluid medium away from said first line means, said second and third line means being separate from one another, first valve means for selectively blocking said second line means with respect to said first line means, second valve means for selectively blocking said third line means with respect to said first line means, and temperature responsive means for controlling said first and second valve means in response to the temperature of the fluid medium in said first line means, said first valve means including a first valve seat and a first valve disc, said first valve disc having a first valve axis extending through a central portion thereof, said first valve seat and first valve disc being movable with respect to one another in the direction of said first valve axis from a position blocking said second line means with respect to said first line means with said first valve seat sealingly engaging a peripheral edge portion of said first valve disc to an open position with said first valve seat spaced from said first valve disc to permit fluid flow from said first line means to said second line means, wherein said first valve seat is formed with a sharp edge tapering conically inwardly toward said first valve axis in the direction facing the flow from said first line means, and wherein said peripheral edge portion on said first valve disc tapers conically inwardly toward said first valve axis in the direction of the flow from said first line means such that said first valve seat and first valve disc form an annular funnel shaped opening diverging in the direction of fluid flow when said first valve seat is moved away from said first valve disc, wherein said first valve seat and first valve disc are configured such that said funnel shaped opening diverges continuously along the entire length of said valve seat and first valve disc in the direction of said first valve axis from the position where said first valve seat and first valve disc abuttingly engage when in said position blocking said second line means with respect to said first line means.
 17. An arrangement according to claim 16, further comprising an internal combustion engine, a vehicle radiator, and a cooling water pump for pumping cooling water to said engine, wherein said first line means is a cooling water outlet line leading from said internal combustion engine, wherein said second line means leads to said vehicle radiator, and wherein said third line means leads to said cooling water pump. 